The trial in Idaho Republican Party v Ysursa has now ended. This is the case in which the Republican Party is fighting to obtain a closed primary for itself. A last round of briefs will be filed in the next few weeks. The decision, when it comes down, will be a landmark. This is the first case in which either major party has submitted empirical evidence that it needs to close its primary because persons not in sympathy with the party have been voting in its primaries. The Democratic Party of Mississippi, and the Republican Party of Virginia, had earlier filed lawsuits to obtain closed primaries for themselves, but no equivalent evidence was presented in either of those cases.
The Mississippi Democratic Party case had lost on a legal technicality, and the Virginia Republican Party had ended with a compromise, in which the party has a right to demand a closed primary for itself only when it is being forced to hold a primary for that particular office.
For more details about the Idaho trial, see blogger Dennis Mansfield’s blog here. Scroll down; not everything on the blog relates to the court case.